超高强度钢薄板扭曲回弹特性的数值模拟与试验分析

Numerical Simulation and Experimental Validation of Distortional Springback of Advanced High-Strength Steel Sheet Metal Forming

为了研究超高强度钢复杂件冲压过程中出现的扭曲回弹现象,设计了可用同一副模具成形的两端开放和一端封闭的2类S梁零件,对其成形后的扭曲回弹特性进行了数值模拟和试验验证.提出了零件整体最大扭曲量的概念,并用其作为评价扭曲回弹程度的指标,分析了压边力、摩擦以及板料轧制方向对于零件扭曲程度的影响.结果表明,在所研究的压边力范围内,扭曲程度随着压边力的减小而减小,摩擦对于2类S梁零件的扭曲回弹的影响呈现不同的规律,在较大压边力和摩擦系数下,采用垂直轧制方向板料成形导致更大的扭曲.研究结果可为预测与减少复杂零件拉深成形扭曲回弹控制提供有益的指导.

In order to study the characteristic of advanced high-strength steel（AHSS） distortional springback,an open forming part S-Rail and semi-open one were designed and stamped using the same draw die.The springback predictions of DP780 under the two process conditions were finished and validated by experiment.A new method to evaluate the distortional springback was proposed,and the impacts of blank holding force,frictional coefficient and material rolling directions to distortional springback were investigated.The results show that,lower blank holding force causes smaller distortion,while no similar rule is found when frictional coefficient changes.Besides,compared with parallel direction blank,vertical direction rolling blank induces larger distortion in the condition of higher blank holding force and frictional coefficient.The results are of help to control the industrial distortional springback.